Illuminating arrangement



June 25, 1963 J. SCHLEIFER 3,0 5, 5

ILLUMINATING ARRANGEMENT Filed May 21, 1959 4 Sheets-Sheet 1 June 25,1963 J. SCHLEIFER 3,095,155

ILLUMINATING ARRANGEMENT Filed May 21, 1959 4 Sheets-Sheet 2 June 25;1963 JQ SCHLEIFER 3,095,155

ILLUMINATING ARRANGEMENT Filed May 21, 1959 4 Sheets-Sheet s INVEA/TURJune 25, 1963 J. SCHLEIFER 3,095,155

ILLUMINATING ARRANGEMENT Filed May 21, 1959 4 Sheets-Sheet 4 FIG. 5

v wws/vroR 3,095,155 4 ILLUMINATEJG ARRANGERENT Josef Sehleifer,Krumhach, Swahia, Germany, assignor to Eugen Bauer, G.m.b.H.,Stuttgm-Unterturkheim, German y Filed May 21, 1959, Ser. No. 814,873Claims priority, application Germany Apr. 23, 1955 6 Claims. (ill.24052) The present invention relates to a new and improved mountingarrangement. More particularly, the present invention relates to a newand improved lamp holding arrangement for light projecting apparatus.

This application is a continuation-in-part of copending application,Serial No. 579,820, filed April 23, 1956 and now abandoned and entitledMounting Arrangement.

In film projecting apparatus, it is common practice to use an elongatedelectrical discharge lamp which is arranged with its longitudinal axisperpendicular to the optical axis of the projector. It is apparent thatin order to obtain the maximum illumination from the discharge lamp, theluminous center of the lamp must be accurately positioned in the lampsupport arrangement for placing said center in the optical axis of theprojector.

Elongated discharge lamps are very fragile lamps and great care must betaken not to unduly stress the lamp when the lamp is to be inserted inthe mounting arrangement and after it is so inserted. On the other hand,it is necessary to grip the lamp properly so as to obtain the accuratealignment of its luminous center with the optical axis of the projector.

In conventional arrangements the lamps are mounted so loosely that theluminous center or" the lamp is readily shifted during operation of theprojector with accompanying loss in light transfer eficiency.

It is accordingly an object of the present invention to provide a newand improved apparatus for overcoming the disadvantages of the prior artarrangements.

A second object of the present invention is to provide a new andimproved apparatus for accurately mounting an elongated electricaldischarge lamp.

Another object of the present invention is to provide a new and improvedlamp holding arrangement having spaced holding members adapted tocooperate with opposite end portions of the elongated discharge lamp.

A further object of the present invention is to provide a new andimproved apparatus for use with an elongated discharge lamp wherein theluminous center of the discharge lamp is accurately positioned by asecurely mounted holding member.

Still another object of the present invention is to provide a new andimproved lamp holding arrangement for use with an electrical elongateddischarge lamp wherein one of two spaced holding members is fixedlymounted with respect to the desired position of the luminous center ofthe lamp and the other holding member is movably mounted with respectthereto while both holding members have a fixed relation to the desiredposition of the longitudinal axis of the lamp.

Still a further object of the present invention is to provide aninexpensive apparatus for accurately supporting an elongated dischargelamp so as to properly position the luminous center thereof.

With the above objects in view the present invention relates to a lampholding arrangement for use with an elongated discharge lamp andincluding a support member, a first holding member adapted to be securedto one end portion of the elongated discharge lamp, means for mountingthe first holding member on the support member immovably relativethereto in axial direction of the elongated discharge lamp at the pointof mounting, a second holding member adapted to be secured to the otherend Patented June 25, 1963 portion of the elongated discharge lamp, andmeans for mounting the second holding member on the support movablyrelative thereto in axial direction of the elongated discharge lamp.

In a preferred embodiment of the present invention the mounting membersare made of electrically conductive material and they are electricallyinsulated from the support member so that energizing conductors for theelectrical discharge lamp may be connected to opposite end portionsthereof.

A further feature of a preferred embodiment of the present invention isthe use of resilient mounting members to relieve any stresses andstrains from the elongated discharge lamp after it is mounted in thelamp holding arrangement.

The novel features which are considered as characteristic for theinvention are set forth in particular in the appended claims. Theinvention itself, however, both as to its construction and its method ofoperation, together with additional objects and advantages thereof, willbe best understood from the following description of specificembodiments when read in connection with the accompanying drawings, inwhich:

FIG. 1 is an elevational view of an embodiment of the lamp holdingarrangement of the present invention shown partially in section;

FIG. 2 is a sectional view taken along the line II-II of FIG. 1;

FIG. 3 is a sectional view taken along the line IIIIII of FIG. 1 androtated therefrom in order to more clearly point out the features of thepresent invention;

FIG. 4 is a partly sectional elevational view of another embodiment of astructure according to the present invention;

FIG. 5 is a sectional view taken along line V-V of FIG. 4 in thedirection of the arrows; and

FIG. 6 is a fragmentary top plan view of the lower clamp structure ofthe FIG. 4.

Referring to the drawings and more particularly to FIGS. 1 and 3, it canbe seen that the lamp holding arrangement is mounted on a support member1 having lower spaced insulators 2 and 3 and upper spaced insulators 4and 5. It can be seen that the insulators 2, 3, 4 and 5 are arrangedsubstantially horizontally in the illustrated figures.

As can best be seen in FIG. 3 a bridging member 6 is fixedly mounted onthe spaced insulators 2 and 3. Mounted above the center portion of thebridging member 6 is a substantially U-shaped leaf spring 10 which isthreadedly mounted on the bridging member 6 by means of screws 8 and 9.It can be seen that the screws 8 and 9 prevent movement of the leafspring 10 at the point of mounting thereof on the bridging member 6. Atthe opposite end portion of the leaf spring 10 is threadedly mounted aholding member 13 which is connected to the leaf spring 10 by means ofscrews 11 and 12.

It can be seen that the free end portion of the holding member 13 has asubstantially U-shaped portion 14 therein and is also formed with arecess 15 of substantially cylindrical shape for accommodating theterminals of a discharge lamp. The holding member 13 is preferably madeof an electrically conducting material and its inner end portion isthreadedly connected to a flexible electrical conductor 16.

In FIG. 1, it can be seen that the holding member 13 is pivotallysupported on the upper end of a pin 7 which is fixed in the bridgingmember 6 so that the member 13 may assume slightly tilted position inany direction within limits determined only by the resiliency of spring10, while the center of recess 15 remains at all times at a fixeddistance from support member 1 horizontally, and at a sufficientlypreset level vertically.

At the opposite upper end of the support member 1, a second bridgingmember 17 is provided which is mounted on the spaced insulators 4 and 5.The bridging member 17 is provided with a bore 18 in which is disposed acoil spring 19. It can be seen that the coil spring 19 in its unstressedcondition is longer than the depth of the hole 18.

Also formed in the bridging member 17 is a second bore 20 which is ofsubstantially smaller depth than the bore 18. Disposed in the bore 20 isa pin 27 the upper end of which is fixedly mounted in a second holdingmember 24. The front end portion of the holding member 24correspondssubstantially to the front end portion of the holding member13. That is the holding member 24 is formed with a substantiallyU-shaped portion 29' and a substantially cylindrical recess at its outerend thereof adapted to cooperate with a terminal of an elongated discharge lamp.

At the inner .endof the bridging member 17 at the upper surface thereof,as best seen in FIG. 2, are provided two projections 22 and 23.Projections 22 and 23 are formed withaligned holes in which is fixedlymounted a pin 21. The inner end of the holding member 24 is formed witha for -shaped portion 26 having a U-shaped recess 25 which cooperateswith the pin 21. As can also be seen in FIG. 2, the side surfaces of thefork-shaped portion 26 of the holding. member 24 are cylindricallycurved so that they may be moved along the inner surfaces of theprojections 22 and 23. Therefore, the member 24 is free to tilt slightlyin any direction since it can turn about the axis of pin 21 and about anaxis perpendicular thereto and to the side walls of the recess 25, whilethe center of recess 29 remains at all times at a fixed distance fromsupport member 1' horizontally. In vertical direction, however, themember 24 is movable within practical limits as made possibly by the pin21 being guided in recess 25, and pin 27 being movable in bore 20.

In FIG; 1, the elongated discharge. lamp is shown mounted in the holdingmembers while in FIG. 3, this lamp has beenremoved in order to clearlyillustrate the new and improved lamp holding arrangement of the presentinvention.

in FIG. 1 it can be seen that the elongated discharge lamp 31 is. formedwith. two opposite terminal portions 32 and 33, the end surfaces 30 ofwhich are substantially planar. It is seen that the terminal portions 30and 32 are substantially cylindrical in shape so as to cooperateproperly with the cylindrical recess 15 in the holding member 13 and thesimilar cylindrical recessin the holding member 24. r

The discharge lamp is also provided with opposite axially arrangedthreaded portions 34 and 35 adapted to cooperate respectively with thumbscrews 36 and 37.

. It must be borne in'mind that elongated discharge lamps for projectorsare so constructed that upon energization there is a luminous centersubstantially in the longitudinal 7 center line of the lamp and at afixed distance from at least one of the terminal ends of the lamp,substantially halfway between the terminal ends. it is, therefore, the

purpose of 'the present device to assure the lamp being held in exactposition for locating said luminous center in the optical axis of theprojector, the support member being itself in a fixed relation thereto.

In operation, the thumb screws 36-and 37 are loosened so as to permitmounting of the lamp 31- in the holding arrangement. The lower threadedportion 34' of the end portion 32 of the lamp 31 is inserted from theside into the U-shaped portion 14 of the lower holding member 13. Thethumb screw 36 is then tightened so that the lamp 31 is supported withits terminal'end 32 in the re-' cess 15 of the lower holding member 13.At this point, since the lower holding member 13 is substantiallyhorizontal, one point of the longitudinal axis of the lamp 31' ispositioned at a predetermined distance from the mounting member 13 andthereby also from the support member 7. At the same time, the luminouscenter thereof is lo- 15. If the terminal portion 32 is thus mounted inthe lower holding member 13 as described hereinabove, the luminouscenter of the lamp 31 will be properly positioned in the projector.

In order to accurately position the luminous center of the elongatedlamp in the axial direction thereof, the pin 7 in the lower holdingmember 13 is initially set so that the location of the holding member 13is correctly related to the support member 1 and to the projector.

When the lamp has been secured to the lower holding ,member 13, theupper end portion '33 is automatically positioned so that the threadedportion 35 thereof cooperates with the U-shaped portion29 of the holdingmember 24. The thumb screw 37 of the upper end portion can now betightly threaded on the threaded member 35 until the lamp is securelyfastened in the holding members.

It is a valuable feature of this device that under the action of spring19 the upper'hold-ing member 24 is normally lifted so as to clear theend of the terminal port-ion 33. at 30 and thereby to permit the lamp 31to be inserted into the holders with only one hand of the operator.

It can be seen that neither the lower holding member 13 nor the upperholding member 24 can be displaced in a direction perpendicular to thelongitudinal axis of the lamp 31. Accordingly, the longitudinal axis ofthe lamp 31 is accurately positioned. However, since the upper holdingmember 24 as well as the lower holding member 13 is resiliently mountedon the support member by means of the compression spring 19, and theblade spring :10, respectively, any stresses or strains that mightotherwise be produced in the lamp 31 are taken up by the resilience ofthe springs. That is, the holding member 24 is free to pivot about thepin 21 in the bridg ing member 17. This pivoting motion is only limitedby the amount of play on the pin 27 in the bore 20 of the bridgingmember. Also, as mentioned hereinabove and as seen in 'FIG. 2, since theside surfacesof the fork shaped portion 26 of the hold-ing member 24 arecylindrical, it is possible for the upper holding member 24 to assume aslightly tilted position sideways in case the face 30 should not besquare with the longitudinal axis of the lamp 31. In addition, thevertical movability in direction of pin 27 makes it possible toaccommodate different tube lengths.

In a similar manner, the lower holding member 13 is free to pivot in alldirections about the tip of pin 7- due to'the resiliency of spring 10for accommodating the end face of the terminal portion 32 should thisface be particular, it will be seen that the structure of FIG. 4

includes a support means made up in part of a stand 51 which can befixedly or movably mounted within an untillustrated housing of aprojector. The stand 51 carries at its bottom end a pair of electricallynon-conductive support portions 52 and 53 and at its top end the stand51 fixedly carries a pair of'electrically non-conductive supportportions 54 and 55, the elongated support portions 52-55 extendinghorizontally, as illustrated.

A bridge member 56 extends between and is fixedly carried by theinsulating support portions 52 and 53, and this bridge member 56 in turnfixedly carries at a substantially central portion thereof which islocated substantially midway between the supports 52 and 53 a pin 57which projects upwardly beyond the top face of the bridge 56 through aslight distance, as is clearly shown at the lower part of FIG. 4. A pairof screw members 58 and 59 (FIG. 6) serve to fixedly connect asubstantially U-shaped leaf spring 60 to the bridge member 56 with theleaf spring 60 located in a horizontal plane. This leaf spring 60fixedly carries by means of a pair of screw members 61 and 62 a carriermeans 63 which includes an intermediate plate portion 64. This plateportion 64 of the carrier means 63 is connected through the screwmembers 65 and 66 to an electrical conductor 67. A fixed jaw 68 isfixedly connected with the carrier means 63 as by being formedintegrally with the latter, and a movable jaw 69 is movable with respectto the fixed jaw 68 (FIG. 6), the carrier means 63 together with thefixed jaw 68 and movable jaw 69 forming a clamp which is carried by thesupport means which is formed by the stand 51, the supports 52 and 53,the bridge 56, and the leaf spring 60.

This lower clamp of the assembly includes an addition to the carriermeans 63 and the jaws 68 and 69 a screw member 70 which extends freelythrough a bore of the movable jaw 69 and which is threadedly connectedwith the fixed jaw 68 so as to be carried by the latter. The movable jaw69 has a considerable play with respect to the screw member 70. Theplate portion 64 of the clamp 63 slidably engages a top surface portionof the movable jaw 69 so as to prevent the latter from turning aroundthe screw member 76. Thus, FIG. 4 shows the surface portion 71 of themovable jaw 69 slidably engaging a part of the plate portion 64 so thatthe jaw 69 cannot turn while at the same time being freely movable alongthe screw 7% toward and away from the fixed jaw 68. The movable jaw isin fact resiliently urged toward the stationary jaw in a mannerdescribed below with respect to the upper clamp of the assembly, thejaws of both clamps cooperating with each other in an identical manner.

The upper insulating support portions 54 and 55 of the support means areconnected to each other by means of an upper bridge 72 which is providedat its ends with clamping rings 73 surrounding and clamped to theinsulating supports 54 and 55. The bridge 72 carries a bearing blockportion 74 which is integral with the bridge 72, and this bearing blockportion 74 has a pair of upstanding cars which fixedly carry anelongated rod 75 extending across the space between the upstanding earsof the beating block 74. The upper clamp of the assembly includes acarrier means 77 which is formed at its left end portion, as viewed inFIG. 4, with an elongated slot 76 extending upwardly from the bottomsurface of the carrier means 77 and through which the rod 75 freelypasses so that the rod 75 cooperates with the slot 76 to guide thecarrier means 77 for vertical movement with respect to the horizontalrod 75 and also for turning movement around the latter. However, it willbe noted that the rod 75 cooperates with the slot 76 to restrain thecarrier means 77 from movement to the right or left, as viewed in FIG.4. Screws 78 serve to connect an electrical conductor 79 to theelectrically conductive carrier means 77 of the upper clamp.

The carrier means 77 of this upper clamp fixedly carries a fixed jaw 77and this upper clamp further includes a movable jaw 80 formed with abore 81 through which a screw 82 freely passes into threaded engagementwith the fixed jaw 77' so that the screw 82 serves to guide the movablejaw 80 for movement toward and away from the fixed jaw 77', and hereagain there is a substantial play of the screw member 32 in the bore 81of the movable jaw 80 so that while the latter is guided by the screwmember 82 nevertheless it can tilt with respect to the axis of the screwmember 82. The movable jaw 80 has a flat :3 end face 83 located closelyadjacent to a fiat surface 84 of the carrier means 77 so that thesurface 84 cooperates with the surface 83 to prevent turning of themovable jaw around the screw member 82. Thus, the fixed jaw 77', themovable jaw 89 and the carrier means 77 cooperate to form the upperclamp 80 which is illustrated in FIG. 5, this clamp including also thestructure which connects the jaw 89 to the remainder of the clamp.

The bore 81 of the movable jaw 80 is provided with an enlarged boreportion 85 in which is located a coil spring 86 which is coiled aboutthe screw member 82, which has one end engaging a collar 87 of the screw82, this collar 87 forming part of the head of the screw, and which hasan opposite end engaging a shoulder 38 located in the bore 81 betweenthe ends of the latter at the junction between the portions of the bore81 which are of different diameters. Thus, it will be seen that thespring 86 acts as a spring means urging the movable jaw 80 along thescrew member 82 toward the fixed jaw 77'. As was pointed out above, theidentical structure is included in the lower clamp, and thus there is acoil spring surrounding the screw 79 and urging the jaw 69 toward thefixed jaw 68 of the lower clamp which is illustrated in FIG. 6.

The movable jaw 84 fixedly carries a pin 89 having a convexly curvedfree end portion 89 extending beyond the movable jaw 39 into engagementwith the fixed jaw '77 so that the movable jaw 80 can tilt within thelimits of play provided between the bore 81 and the screw member 82around the point of engagement between the end 89' of the pin 89 and thefixed jaw 77. The lower clamp of the assembly includes an identical pinfixed to the movable jaw 69 and engaging the fixed jaw 68 to providelimited tilting movement of the movable jaw 69.

The carrier means 77 of the upper clamp is fixed by suitable screwmembers at its underside to a supporting leaf spring 90 which forms partof the support means for the upper clamp. A coil spring 91 is fixed atits top end to the leaf spring 90 and this coil spring 91 extendsdownwardly along the interior of a bore 92 extending vertically andformed in the bridge 72, this bridge carrying a pin 93 which extendsacross the bore 92 adjacent the lower end of the latter and to which thebottom end of the coil spring 91 is connected so that the spring 91urges the entire upper clamp 80' downwardly to a limiting positiondetermined by the upper surface of the bridge 72. In other words, thisupper surface of the bridge 72 forms a stop which limits the downwardmovement of the upper clamp 80'.

As is shown most clearly in FIGS. '5 and 6, the pairs of cooperatingjaws of the clamps are respectively formed with concave curved sidesurface portions 94 directed toward each other, and these surfaceportions 94 of the pairs of jaws form parts 'of a common cylinder. Nextto the arcuate concave surface portions 94 the jaws are provided withflat surface portions 95 directed toward each other, and at their freeend portions each pair of cooperating jaws has oppositely inclinedsurface portions 96 directed toward each other, these oppositelyinclined surface portions 96 diverging away from each other as theyapproach the extremity of the free ends of the jaws, so that in this wayintroduction of the article to be clamped into the space between thejaws is facilitated.

The above-described structure of the invention is adapted to support alamp 97, which may be, for example a xenon high-pressure lamp. This lamp97 is provided at its ends with the exterior sleeves 98 and 99 which arestepped so as to be provided with the shoulders 109 and 161 which aredirected away from each other, and these sleeves terminate incylindrical free end portions 102 and 103 located beyond the shouldersand 101, respectively.

When the lamp 97 is not connected to the structure of the invention, thesprings 8-6 of the clamps locate the movable jaws thereof nearer to thefixed jaws than these jaws are located when the lamp is supported by theapparatus of the invention. The springs 86 tilt the movable jaws aroundthe curved ends 89 of the pins 89 so as to locate the free end portionsof the movable jaws nearer to the fixed jaws than these free endportions of the movable jaws are located when the cylindrical free ends102 and 103 of the lamp are clamped. Also, when the lamp 97 is notconnected to the structure of the invention, the spring 91 locates theleaf spring 99 in engagement with the upper stop surface of the bridge72, and at this time the upper clamp 89 is located nearer to the lowerclamp than when the lamp 97 is carried by the apparatus of theinvention. In other words, when the lamp is not connected to theapparatus the jaws of the upper clamp 80 are located at a distance fromthe jaws of the lower clamp which is less than the distance between theshoulders 160 and 191 of the lamp 97.

'When mounting the lamp 97 on the apparatus of the invention, the uppercylindrical free end portion 192 of the lamp is first introduced intothe upper clamp 80. This is done simply by advancing the upper end 182of the lamp to the left, as viewed in FIG. 4, first between theoppositely inclined diverging surface portions 96 of the jaws of theupper clamp, so that the end portion 102 of the lamp 97 easily slidesinto the space between the jaws and moves the movable jaw 89 away fromthe fixed jaw 77, the operator continuing to advance the lamp toward theleft, as viewed in FIG. 4, until the cylindrical upper end portion 1452of the lamp snaps into the space between the surface portions 94 of thejaws, and then these surface portions are resiliently pressed againstthe exterior cylindrical surface of the upper end portion 192 of thelamp 97. The upper end portion 182 of the lamp 97 'forms a cylinderwhich is of the same diameter as that of which the surface portions 94-form a part.

At this time, the'lamp 97 is inclined downwardly to- .ward the right, asviewed in FIG. 4, since only the upper end of the lamp has beenintroduced into the upper clamp 86', but the upper clamp can freelyadapt itself to this inclination because of the tiltability provided bycooperation of the pin 75 and the slot 76. The operator can now lift theentire upper clamp Sil together with the lamp 97, the slotted portion 76simply moving upwardly with respect to the pin 75 at this time, and inthis way the operator can locate the lower cylindrical free end 193 ofthe lamp 97 in alignment with the lower clamp of the invention, and nowthe operator simply presses the lower cylindrical end 1030f the lamp 97into the space between the jaws of the lower clamp in the same way thatthe upper end 102 of the'lamp was introduced into the space between thejaws of. the upper clamp. Now when the operator releases the lamp, thespring 91 will move the upper clamp 80' together with the entire lamp97' downwardly until the shoulder 101 of the lamp engages the topsurfaces of the jaws 6S and 69 and until the carrier 63 of the lowerclamp engages the top end of the pin 57. The

, coil springs 86 serve to resiliently clamp the ends of the lampbetween the pairs of jaws. Now the operator can tighten the screws 82and 70 so as to fix the ends of the lamp in the jaws of the clamps. Asmay be seen from FIG. 5, the collar 87 of the screw 82 has a diameterlarger than the enlarged portion 85 of the opening 31 of the movablejaw, so that While the screw members can be unloosened to be locatedwith their head ends sufiiciently spaced from the movable, jaws toprovide a desired yieldable movement of the latter, at the same time thescrews can be tightened with their head ends directly engaging themovable jaws and acting entirely independently of the springs 86 fortightly clamping the ends of the lamp between the jaws of the clamps.Because of thistight clamping of the ends of the lamp as well as becauseof the fact that the surfaces 94 form portions of a cylinder of the samesize as the exterior surfaces of the ends of the lamp, an extremelysuperior transfer of electrical current takes place between the clampsand the lamp. It should be noted that the tiltability of the movablejaws provided by the free ends 89' of the pins 89 also con tribute tothe complete adaptability of the jaws to the ends of the lamp so as toprovide the desired large area of high pressure contact between the lampand the clamping jaws and in this way guarantee the efiicient transferof electrical current.

The engagement between the carrier means 63 of. the lower clamp with thetop surface of the pin 57 guarantees location of the lamp 97 properlywith respect to the optical axis of the projector. The leaf spring 60prevents movement of the lamp transversely to its axis while at the sametime providing a limited yieldable tiltability of the lower clampingjaws 68 and 69 so that the latter can adapt themselves to the lampwithout stressing the lamp.

As was pointed out above, the rod 75 cooperates with the slot 76 to alsoprevent movement of the upper clamp to the right or left, as viewed inFIG. 4, with respect to the axis along which the lamp 97 extends, andhere again the cooperation of the pin 75 with the slot 76 permits theupper clamp at its jaws 77 and 80 to yieldably adapt themselves to theattitude of the lamp during the mounting of the latter on the apparatusof the invention.

Thus, while the clamp structure of the embodiment of FIGS. 1-3 issomewhat simpler than that of FIGS. 4-6, nevertheless by providing theabove-described structure of P168. 4-6 the inconvenience of the nuts 36and 3-7 is avoided and a far superior electrical connection is providedwith the embodiment of FIGS. 4-6.

What is claimed as new and desired to be secured by Letters latent is: a

l. Lamp-holding arrangement for holding a discharge lamp at oppositeends thereof, comprising, in. combination, a rigid support member; afirst rigid holding member; a'second rigid holding member; firstsecuring means for rigidly clamping said first holding member firmly toone end of said lamp; second securing means for rigidly clamping saidsecond holding member firmly to the opposite end of said lamp, saidfirst and second securing means defining a mounting axis for said lamp;first mounting means mounting said first holding member to said supportmember immovably in direction of said mounting axis away from saidsecond holding member and in direction transverse to said axis, buttiltably in all directions relative thereto; and second mounting meansmounting said second holding member to said support member'immovably indirection transversally of said mountingaxis but movably in directionthereof and tiltably in all directions relative thereto.

2. Lamp holding arrangement for holding an elongated discharge lamp atopposite ends thereof, comprising, in combination, a rigid supportmember, a first rigid holding member; a second rigid holding member,each of said holding members being provided with a'recess for receivingthe corresponding end of said lamp, said recesses of said first and saidsecond holding members, respectively, facing each other and beingprovided each with a radial slot for accommodating axially projectingstuds that may form part of said ends of said lamp, and each of saidholding members being made of electrically conductive material and areelectrically insulated from said support member so that energizingconductors for the lamp may be connected to said holding members forpplying energy to said lamp; first securing means for rigidly clampingsaid first holding member firmly to one end of said lamp; secondsecuring means for rigidly olampcluding a blade spring attached with oneportion thereof to said support member and with another portion thereofto said first holding member for connecting said support member withsaid first holding member, and a support element fixedly mounted in saidsupport member underneath said first holding member and contacting thelatter in one point located between said two portions of said spring soas to enable said first holding member to tilt in various directionsaround said one point during flexing of said spring; and second mountingmeans mounting said second holding member to said support memberimmov-ably in direction transversal of said mounting axis but movably indirection thereof and tiltably in all directions relative thereto, saidsecond mounting means ineluding hinge means for movably connecting saidsupport member with said second holding member and said hinge meanscomprising a hinge pin fixedly mounted in said support member andextending in a direction substantially perpendicular to said mountingaxis, and a slot provided in a portion of said second holding memberremote from said recess thereof, said slot slidably embracing said hingepin for enabling said second holding member to move both turningly aboutthe axis of said pin and about an axis perpendicular to said slot, alsoin a direction which is simultaneously perpendicular to said slot, andparallel with said mounting axis, while being prevented from moving in adirection which is substantially perpendicular to said pin and to saidmounting axis.

3. A lamp holding arrangement as defined in claim :1 in which said firstmounting means includes a blade spring attached with one portion thereofto said support member and with another portion thereof to said firstholding member; and means mounted on said support member and engagingsaid first holding member for preventing movement of the latter indirection of said mounting axis away from said second holding memberwhile permitting tilting of said first holding member in all directionsrelative to said mounting axis.

4. A lamp holding arrangement as defined in claim 3 in which said lastmentioned means comprises a support 10 element fixedly mounted on saidsupport member underneath said first holding member and contacting thelatter substantially in one point between said two portions of saidblade spring.

5. A lamp holding arrangement as defined in claim 1 wherein said secondmounting means comprises hinge means for connecting said second holdingmember to said support member immovably in direction transversally ofsaid mounting axis but movably in direction thereof and tiltably in alldirections relative thereto.

6. A lamp holding arrangement as defined in claim 5 wherein said hingemeans comprises a hinge pin fixedly mounted in said support member andextending in a direction substantially perpendicular to said mountingaxis, and a slot formed in said second holding member and slidinglyembracing said hinge pin for enabling said second holding member to moveboth turningly about the axis of said pin and about an axisperpendicular to said slot and also in a direction which issimultaneously perpendicular to said slot and parallel with saidmounting axis, while preventing said second holding member from movingin a direction which is simultaneously perpendicular to said pin and tosaid mounting axis.

References Cited in the file of this patent UNITED STATES PATENTS

1. LAMP-HOLDING ARRANGEMENT FOR HOLDING A DISCHARGE LAMP AT OPPOSITEENDS THEREOF, COMPRISING, IN COMBINATION, A RIGID SUPPORT MEMBER; AFIRST RIGID HOLDING MEMBER; A SECOND RIGID HOLDING MEMBER; FIRSTSECURING MEANS FOR RIGIDLY CLAMPING SAID FIRST HOLDING MEMBER FIRMLY TOONE END OF SAID LAMP; SECOND SECURING MEANS FOR RIGIDLY CLAMPING SAIDSECOND HOLDING MEMBER FIRMLY TO THE OPPOSITE END OF SAID LAMP, SAIDFIRST AND SECOND SECURING MEANS DEFINING A MOUNTING AXIS FOR SAID LAMP;FIRST MOUNTING MEANS MOUNTING SAID FIRST HOLDING MEMBER TO SAID SUPPORTMEMBER IMMOVABLY IN DIRECTION OF SAID MOUNTING AXIS AWAY FROM SAIDSECOND HOLDING MEMBER AND IN DIRECTION TRANSVERSE TO SAID AXIS, BUTTILTABLY IN ALL DIRECTIONS RELATIVE THERETO; AND SECOND MOUNTING MEANSMOUNTING SAID SECOND HOLDING MEMBER TO SAID SUPPORT MEMBER IMMOVABLY INDIRECTION TRANSVERSALLY OF SAID MOUNTING AXIS BUT MOVABLY IN DIRECTIONTHEREOF AND TILTABLY IN ALL DIRECTIONS RELATIVE THERETO.